Multi-image Photogrammetry for Underwater Archaeological Site Recording: An Accessible, Diver-Based Approach

Abstract

This article presents a discussion of recent advances in underwater photogrammetric survey, illustrated by case studies in Scotland and Denmark between 2011 and 2013. Results from field trials are discussed with the aim of illustrating practical low-cost solutions for recording underwater archaeological sites in 3D using photogrammetry and using this data to offer enhanced recording, interpretation and analysis. We argue that the availability of integrated multi-image photogrammetry software, highly light-sensitive digital sensors and wide-aperture compact cameras, now allow for simple work flows with minimal equipment and excellent natural colour images even at depths of up to 30 m. This has changed the possibilities for underwater photogrammetric recording, which can now be done on a small scale, through the use of a single camera and automated work flow. The intention of this paper is to demonstrate the quality and versatility of the ‘one camera/ambient light/integrated software’ technique through the case studies presented and the results derived from this process. We also demonstrate how the 3D data generated can be subjected to surface analysis techniques to enhance detail and to generate data-driven fly-throughs and reconstructions, opening the door to new avenues of engagement with both specialists and the wider public.